请帮我分析一下这个句子
问题描述：
请帮我分析一下这个句子
a child trying to squeeze through the iron fence became stuck between two bars,but luckily she was able to extricate herself.
1.我想问一下,became stuck 这里是怎么回事,不是一个句子只能有一个谓语么?前面的trying to squeeze 是谓语?
答
a child（trying to squeeze through the iron fence 后置定语）became（系动词）stuck（表语）
一个小孩（什么样的小孩?试着从铁栏杆里的缝隙钻过去的小孩）卡在两根铁杆里了,但幸运的是,她还是把自己解救出来了